At the heart of the Sigma LW range of antennas is the 9:1 UNUN. This provides a feedpointfor the long wire radiating element and converts the impedance from 450 Ohms (+/-) tosomething nearer to the 50 Ohms expected by your transceiver.

There are three connectionson the UNUN , a SO-239 to which you connect the coaxial feed line and two machine screwswith butterfly wing nuts.

One of these has the wire antenna connected to it and the other is for you to connect a length of wire to earth.

This is not strictly a necessary connection but will reduce static pick up and provide a direct to earth for any possible lightening strike or buildup of static in the air.

The best way to do this is to attach a length of wire to a ground rod andfix it to the UNUN at this terminal.

Fix the feed point up as high as possible – it may be attached to a pole or to a wall and then attach the other end of the wire to a point as faraway as is possible.

This is best done if the wire can be kept in a straight line and horizontal but , if this is not possible due to space restriction, do not despair.

The wire may be doglegged, sloped or fixed in any number of ways to enable it to fit in a space available.

The LW-40 will operate on all HF bands from 160m upwards with a good ATU.

The other end of your coaxial cable should be attached to your ATU and then from the ATUto yourtransceiver. Power up, make final adjustments to tune and away you go.